Rectangular pot-type oil burner



Patented Oct. 3, 1950 ENT -oFFlc-E.

REcTANGULAn'Por-TYPE ou. BUnNEn Clarence A. Miller, John Thomson, and Frank J. Ryno, Petaluma, Calif., assignors to Kresky Mfg. Co., Inc., Petalumm-Calif., a. corporation Y L of California Application March 8, 1947,v serial No. 733,292

' 7 Claims. (Cl. 15S- 91) This invention relates to oil burners and, more particularly, to improvements in oil burners of the stimulated or natural draft pot type.

The present invention is in the nature of an improvement in oil burners of the type disclosed in Kresky Patent No. 1,912,713, issued June 6, 1933, and the patent to Miller, No. 2,391,585, issued December 25, 1945.

It is a principal object of the present invention t provide an oil burner wherein air is furnished to the fuel oil utilized in the burner in a manner, generally, to improve combustion eiliciency.

It is a more specific object of the present invention to provide an oil burner wherein the burner is formed to admit air to the area of prime combustion and the area of secondary combustion in the mixing and combustion chamber in order to effect maximum combustion eiiiciency of the oil and to complete combustion of the volatile gases Y within a given range, thereby avoiding undesirable heat (and fuel) loss.

It is a further object of the present invention to provide an oil burner ofthe character mentioned wherein a plurality of different types of fuel oil may be burned with eilicient results.

It is to be noted that-in recent years a so-called catalytic process of cracking crude oils has been developed to a high degree of efllciency in order to supply great quantities of high octane gasoline. In the process of producing high octane gasoline a correspondingly large quantity of light fuel oil is also produced which contains high percentages of carbon and is chemically unstable when utilized as fuel in vaporizing type oil burners of the character of the instant type oil burner, namely, a forced or natural draft pot type burner. The practical problem has arisen wherein known oil burners of the aforementioned character can not operate efliciently with the so-called catalytic type fuel oil which currently forms a large part of the fuel supply. It is, therefore, a specific object 0f the present invention to provide a forced or natural draft pot type oil burner, which is adapted to utilize so-called catalytic type fuel oils, as well as other fuel oils, eiiiciently and economically.

It is a further object of the present invention to provide an oil burner adapted to introduce air, under forced or natural draft, intothe mixing and combustion chamber in a manner which prevents development of static pressure" within the combustion chamber. So-called static pressure within a mixing and combustion chamber refers to obstruction 0r impedance of air flowing into a said chamber which causes a bac'k flow of the air .so introduced in the direction of the flow of the air into the said chamber. "Static pressure created within the mixing and combustion chamber causes undesirable current eddies and turbulence which the present invention obviates.

In the present invention, we have provideda directional-flow to the airintroduced into the mixing and combustion chamber which may be described, generally. as inthe direction of llame travel, namely, toward the chimney of the oil burner.

It is a further object of the present invention to provide an oil burner wherein the gases of combustion are enabled to expand upwardly within the mixing and combustion chamber in the direction of secondary combustion. We prefer to restrict the area of combustion at the point of initial or prime combustion, adjacent to the surface of the fuel oil, and to allow the volatile gases to expand upwardly so that, when Secondary air is admitted to the point where the carbon is in suspension and most susceptible to oxygen, there is insured a complete combination of oxygen and carbon within the combustion chamber. It might be noted in this respect that introduction of air at the point of prime combustion, adjacent to the surface of the fuel oil, is essentially to dissipate the hydrogen content of the fuel oil, thereby freeing the carbon contained in the fuel oil for combination with oxygen at the secondary stage of air introduction into the mixing and combustion chamber.

A further specific object of the present invention is to provide an oil burner wherein air is introduced into the mixing and combustion chamber insa free owing directional manner without the creation of turbulence or eddies; in other words, to provide an oil burner wherein lair may be introduced into the mixing and combustion chamber in a controlled, directional flow whereby all the oxygen of the air so introduced will be utilized in the combustion process.

A further objectof the present invention is to provide a relatively simple to manufacture oil burner, which is sturdy of construction, simple of operation and wherein combustion eciency is maximum from the standpoint of maximum utilization of fuel to produce usable heat without heat or fuel waste. The present invention is adaptable for use in a wide variety of domestic and industrial appliances, such as Water heaters, space heaters, furnaces of various types, and many other articles of manufacture or similar operation. The present invention is readily adapted for installation in many appliances of the type mentioned of conventional design without necessity for redesign and reconstruction thereof.

Other objects and advantages of the present invention will become apparent upon referring to the accompanying specification and drawings in which similar characters of reference represent corresponding parts in each of the several views.

Referring to the drawings:

Fig. 1 is a longitudinal, sectional view of an oil burner embodying our invention.

Fig. 2 is a sectional view, taken on line 2-2 of Fig. 1.

Fig. 3 is a top plan view of the burner.

The present invention comprises, essentially, an elongated hollow top casting A and an c1011- gated lower casting B enclosed partially Within a preferably rectangular air box C. A fuel oil supply pipe is indicated at D, and an air pipe leading to a. suitable pressure generative force, such as a blower (not shown), is indicated generally as at E. A door J is provided in the air box C in the event it is desired to use natural rather than forced or stimulated draft effected by a blower or the like.

The lowering casting B comprises a sump portion 2, to which the fuel oil pipe C is connected. The bottom floor 3 of the lower casting is inclined slightly from opposite ends toward the sump 2 and opposite ends of the said lower casting are provided with `-steps 4. The purpose of the inclined bottom floor of the lower casting B and steps 4 is to enable a gradual spread of oil over the floor so that an increasingly -larger area of fuel oil is provided during initial stages of iilling of the fuel reservoir, which comprises the bottom portion of the casting B. The gradual spread 0f oil over an increasingly larger oor surface enables quick ignition of the fuel and makes possible an immediate hot flame. The end walls 5 of the casting B are each provided with a bench or shoulder 6, upon which the imperforate end walls 1 of the top casting A rest, when the top casting is positioned within the bottom casting, as will hereinafter more fully appear. The bench is disposed approximately at the level of oil contained in the masting B when the burner is in operation, or slightly above the level of said oil.

The lower casting B is provided with side walls 8. These walls are preferably generally arcuate in cross section, as particularly indicated in Fig. 2, and are spaced laterally outwardly from the side walls, generally indicated at 9, of casting A. The curvature of the inner sides of walls 8 is inwardly from top to bottom and it is noted that there are no right angular obstructions in the path of air flowing from the top of the bottom casting to the bottom thereof. Hence, as hereinafter mentioned, undesirable turbulence and air eddies are prevented.

The top casting A comprises end and side walls 'I and 9, each provided with peripheral side and end flanges II and I2. The end flanges I2 are connected by bolts I3, or the like, to the air box C and the side flanges II are adapted to be supported by shoulders l5, carried by the air box, and are also bolted to ears I6 of lower casting walls l. The lower casting B is spaced within the rectangular air box C so that air, flowing through pipe E into the air box in the direction of the arrow (Fig. 1), or through the open door J, will have free access to flow around the said casting -B and between the bottom of fianges II and the walls l, substantially as indicated by the arrows in Fig. 2. The air box C is provided with a top opening as is the top casting as at I9, through which the llame travels from the mixing and combustion chamber defined by the walls of the said top casting A.

The hollow top casting A is provided with inner peripheral end baille portions I8. The walls 8 0f the top casting rest upon the casting B at approximately the level of the bench portions 6 and above the floor 3 of the lower casting A. The bottoms of walls 9 normally are disposed at approximately the level of the fuel contained in the bottom casting when the burner is in operation, as indicated at G in Fig. i, or slightly above the said fuel level.

Itis a feature of the present invention that the walls B are inclined toward one another relative to the horizontal or level of the fuel oil adapted to be contained in the bottom casting. We have found that vastly improved combustion eiliciency may be attained when the walls B are so disposed angularly relative to'the horizontal within a range of 60 to 80. However, preferably, we disposed the walls 9 at an angle of approximately 74 relative to the horizontal, as indicated at H in Fig. 2. We have found that the mentioned angular disposition of the said walls, namely, approximately 74 relative to the horizontal or oil level in the bottom casting, enables m ximum combustion efficiency heretofore unatt inable. Burning efficiency developed from the specified range of angular displacement of walls 8 to the horizontal and particularly the preferred angular displacement of 74 relative to the horizontal is best practically attainable when the height of Walls 9 are equal to or not more than about three times greater than the distance between the walls 9 at oil level. Obviously, conditions of air pressure (forced draft), amount of fuel to be consumed, and other operating factors enter into the problem, but for practical, workable and highly eificient operating burners of the type herein described, the stipulated range and preferred angles of wall displacement give best results.

We prefer to provide a plurality of spaced notches 2| in the bottom edges of the walls 9 in order to enable slightly greater inflow of air into the mixing and combustion chamber at the point of prime combustion, i. e. adjacent to the surface of the fuel oil.

Further, we have found that if fuel oil is introduced into the mixing and combustion chamber at a rate in excess of the burning capacity thereof, as is sometimes the case, there may be lateral flow of oil through the slots against the side walls of the bottom casting without obstructing deleteriously the flow of air into the said chamber and hence without hampering combustion efficiency of the unit. Throughout the surface of walls 9 there is provided a plurality of holes, designated as 22, which are provided in the walls 9 perpendicular thereto and arranged from top to bottom of the said walls. Hence air flowing from the air box into the distribution chambers F, defined by the inwardly curved walls Il of the bottom casting and the walls 9, is dispersed from the said distribution chambers F in the mixing and combustion chamber K at an angle commensurate with the angle of disposition of the walls 9 relative to the horizontal. Thus when the walls are disposed at an angle of 74 relative to the horizontal, air is inducted, under pressure, into the mixing and combustion chamber through the holes at an angle of 16 relative to the horimntal.

The air is introduced from distribution chambers F into the mixing and combustion chamber in an unobstructed directional flow and the air directed into the said chamber, through holes 22, coupled with the inherent upward name travel of the combustion gases, causes air, introduced through slots 2| at the point of initial or prime combustion, to be pulled or sucked upwardly and prevents formation of static pressure adjacent to the surface of the fuel oil. The arcuate, rounded walls 8 of bottom casting B, in combination with the inclined or inwardly sloped walls 9 of casting A, enable a free, unobstructed flow of air from chambers F `into the mixing and combustion chamber K, obviating undesirable turbulence and air currents which inhibit, rather than improve, combustion emciency.

We have found that the present invention enables the combination of oxygen with carbon to eiect complete combustion. We ascribe the new results, in good part at least, to the means to impart directional flow of primary and secondary air into the'mixing and combustion chamber comprising deployment of the walls 9 at an incline toward one another from top to bottom and preferably, at an angle of approximately 74, relative to the horizontal or fuel level. We, further, have found that the walls of the top casting or mixing and combustion chamber must be suitably inclined relative to the horizontal and not merely the apertures through which the air is introduced into the combustion chamber. Unsatisfactory results were obtained in drilling the holes obliquely through vertically disposed combustion chamber walls. While we have described the present invention in more or less precise detail, for purposes of clarity of illustration and example, it is to be understood that various changes, arrangements and modifications may be made in certain parts and portions of the oil burner without departing from the spirit of the invention and is Within the scope of the appended claims.

We claim:

1. In an elongated rectangular pot type oil burner, the combination comprising an elongated bottom casting having arcuate side walls, a floor portion and a sump portion, said floor portion sloping slightly from opposite ends toward said sump portion, means to supply oil to the sump portion, an elongated hollow top casting having side walls and end walls partially inserted within said bottom casting so that the side walls thereof are spaced inwardly from the arcuate side walls of the bottom casting, said side walls of said to-p casting provided with a plurality of apertures arranged from top to bottom thereof. said side walls inclined toward one another equiangularly within a range of from 60 to 80 relative to the horizontal from top to bottom and substantially throughout their entire height, and an air box partially enclosing and spaced from said top land bottom castings and in flow communication with the spaces between said arcuate walls and said angularly disposed walls of said bottom and top castings respectively, said side walls being of a height at least equal to and not more than about three times the width between said side walls at the normal operating level of oil in said sump portion.

2. In an elongated rectangular pot type oil burner, the combination according to claim l and wherein'said angularly disposed side walls of said top casting are disposed at approximately 74 relative to the horizontal.

3. In an elongated rectangular pot type oil burner, the combination of an elongated bottom 6 casting having a floor, end walls and arcuate side walls, means to supply fuel oil to the floor of the bottom casting, a hollow, elongated top casting having end walls and depending side walls, said side walls adapted to fit in said bottom casting and spaced inwardly from said side walls of said bottom casting to form air-distributing chambers,

each said side Wall of said top casting provided to the bottom thereof within a range of from 60 1 to relative to the horizontal and so that the space between said side walls adjacent to the level of fuel oil is less than the distance between the tops of said side walls, and means to supply air under pressure to said air distributing chambers.

4. In an elongated rectangular pot type oil burner, thecombination of an elongated bottom casting having a fuel reservoir portion and end and side walls, means to supply oil to said reservoir portion of said bottom casting, an elongated hollow top casting having end walls and side walls disposed partially within said bottom casting, said side walls of said top casting spaced inwardly from said side walls of said bottom casting to form therebetween air-distributing chambers on opposite sides of said oil burner, each said side wall of said top casting provided with a plurality of holes disposed perpendicularly to a said side wall and arranged from top to bottom thereof, said latter side walls inclined toward one another equiangularly substantially throughout their entire height within a range of 60 to 80 relative to the horizontal so that the bottoms of said sideY walls are closer to one another than the tops thereof, and an air box surrounding said castings and in flow communication with said air-distrib' uting chambers, said side walls being of a height at least equal to and not more than about three times the width between said side walls at the normal operating level of oil in said reservoir of said bottom casting.

5. In an elongated rectangular pot type oil burner, the combination according to claim 4 and wherein said side walls of said top casting are disposed at an angle of approximately 74 rela-- tive to the horizontal.

6. In an elongated rectangular pot type oil burner, the combination of an elongated bottom member having a fuel reservoir portion and end and side walls, means to supply oil to said reservoir portion of said bottom member, an elongated hollow top member having end walls and side walls disposed partially Within said bottom casting, said side walls of said top member spaced inwardly from said side walls of vsaid bottom member to form therebetweenair-distributing chambers on opposite sides of said oil burner, each said side wall of said top member provided with a plurality of holes disposed perpendicularly to a said side Wall and arranged from top to bottom thereof, said latter side walls inclined substantially equiangularly toward one another from top to bottom substantially throughout their entire height and within a range of from 60 to 80 relative to the horizontal so that the bottoms of said vside walls are closer to one another than the tops thereof, and means to supply air under pressure to said air-distributing chambers.

7. In a pot type oil burner, the combination of a bottom member having a fuel reservoir portion and a pair of opposltely positioned upwardly extending side walls, said upwardly extending side walls being closer together at their bottoms than at their tops, means to supply oil to said reservoir portion of said bottom member. a hollow top member having a pair of oppositely positioned downwardly extending side walls projecting into said bottom member and alongside said upwardly extending side walls, end wall means at each end portion of both said top and bottom members extending between the end portions of said upwardly extending pair of walls and between the end portions of said downwardly extending pair of walls, each upwardly extending wall and its adjacent downwardly extending wall being spaced apart and said space constituting an air distributing chamber on opposite sides oi' the burner, each said side wall of said top member provided with a plurality of holes disposed penpendicularly to said side wail and arranged from top to bottom thereof, said latter side walls inclined substantially equiangularly toward one another from top to bottom substantially throughout their entire height and within a range of from 60 to 80 relative to the horizontal so that the bottoms ot said side walls are closer to one another than the tops thereof, and means td, supply air under pressure to said air-distributing chambers.

CLARENCE A. I\IIII.J..ER.-

JOHN THOMSON.

FRANK J. RYNO.

Name Date 1,912,713 Kresky June 6, 1933 2,391,585 Miller Dec. 25, 1945 2,393,176 Livar et al Jan. 15, 1946 2,420,981 Rivers May 20, 1947 i 

